Emile andreoli



' (No Modell.)

, E. ANDRB0'LI.

APPARATUS POR ELEUTRODEPSITION 0F GOLD 0R SILVER.

No.l 568,724.

i '"Ilmll rum. n: umm-mln.;

side of the' cathode' which facesthe anode.

goldand silver solutions.

` fnnutn ANDREOLI, oF tonnen, ENGLAND.

, ,ADPRATUS.FoRVELCTRODEPOSITION'oF GOLD ORSILVER.-

' sPEcIFicATIoN 'forming part of Letters Patent No. 568,724, aateaoctober 6,- 1896.

I".tppicnivnfina Juiy'lo, 1895. stanno.

thontf t vmay concern.- 4 1t known that I, EMILE ANDREOLI, a citizen of France, residing at Somerleyton Road,

.S V. London, in the county of Surrey, England,` have invented certain new and useful .Improvements in the Electrodepositio'n of Gold'or Silver, (patented in Great Britain `June lS, 1895, No.'11,752,' and in Belgium e April "l, 1895,'No, ll4,959,) ofwhich the followingtis'a full, clear, and exact description'.

- `In t-liie usuali electrodeposition ot' gold or silver earch anode or row of anode's is opposite and near to a cathode, either in a single electrolyte or in two liquids separated by porous cells, and-the metal is only deposited on the According to this invention'I use two anodes Only in` presence of numerous cathodes'and deposit gold and silver from their solution in less time and 011 a muchl larger surface of i cathodes, although iii smaller tanks, than bythe ordinary process. i

will take'as an illust-ration the treatment 'of cyanidofgold and potassium cyanid solution; but'my process is applicable to other i In'carryingV out this inventionI may use a tank without compartments or a tank divided lut'ion, 4and is the negative compartment be in three compartments by porous diaphragms When'there are three vcompartments in the tank, the central 'one contains the gold solution,l say a cyanid of gold and potassium sotween ltwo positive compartments. Theelecf negative compartment. I'

trolyte inthe positive compartments may be varied. I prefer, however, to use a caustic potashorsoda solution, or a cyanid-offgold solution similar to the one electrolyzed vin the may use iron anodes, but I preferably use peroxidized lead asapositive plate, and to the best of my jknowledg'esuch peroXidized-lead anodes have never been employed in avcyanid solution; lAt the bottom of the central compartment'is loweredges of as many perforated. plates orl 59 ganzes or pieces of wire network oframalga-` mated copper or other suitableA metal as the Widtl1of the central compartment allows me a thin layer of mercury, in which a copper or 555,502. (No model.) Patented in Belgium April 1, 1895, No. 114,959, and in England June 1s, 1895.110. 11,752.

to put one against the other, vrmaking good contact with the mercury, in which they stand up and work as a cathode. Thus these amalgamatedplates present the largest surface possible of mercurial cathodes to the gold solution, which .rises from the loottomof the tank and passes through their interstices as through a filter which retains the gold. XVhen 'a sufficient quantity of gold has been absorbed by the amalgamated cathodes, the plates are cleaned 11p and the mercury is retorted inthe ordinary way. The gold solution enters. the

tank at the bottom by means of a pipe or several pipes conveniently disposed over the mercury cathode and escapes through out-A lets in the upper-part of the compartment after it has' yielded its gold to the mercury layer and to the amalgamated perforated plates, ganzes, wire network, and the like.'

lVhen I have several tanks,the gold solution runs from one central compartment toa second, &c., through suitable pipes. The diaphragms are preferably made of porous asbestos or kieselguhrporcelain, mounted 011 suitable frames made of paraiiined wood or slate or similarmaterialand fixed in grooves cut at the bottom and on the walls of the tank,

y where they make Water-tight compartments.

The advantage in employing asbestos or kieselguhr porcelain or their equivalent is that it does not allow the diusion of the cyanid, and that this material is not attacked by alkalies or by cyanid of potassium. Vhen such porcelain cannot be'procured, thecompartments are formed by finely-woven tissues stretched on frames, and in such a case the same gold solution circulates in the three compartments.- or, still better, the electrodepositi'on of gold .takes place in a tank without compartments, as hereinafter described and illustrated.

My invention is `illustrated in th accompanying; drawings, in whichi Figure Vl is a side elevation of thc tank. Fig. 2 is across-section thereof. Fig..3 is a cross-section of a tank without compartments. z

Fig. 4: is a side elevation with lthe Wall broken away'and showing the plates or electrodes dis-l posed crosswise therein. Fig. 5 illustrates a f wire network electrode. ".Fig. 6 illustrates a peroxidized-lead anode. Fig. 7 shows an ar-l IDO rangement of several tanks in a circulating system; and Fig. 8 is a cross-section oflthe'uplayer ot" mercury l,

per part ofthe tank, showin the construction in detail.

A is the tank.

l B are the positive compartiments, con taining a caustic potash or cyanid of gold and potassium solution.

C C are the iron or peroxid-ot`lead anodes.

D is the central compartment, containing the gold solution.

E is the layer of mercury, in which is immersed a copper or other metal F, connected with the negative pole of the generator of electricity by a wire f.

G G G are the amalgamated perforated plates, which dip in the mercurial cathode.

Il is the pipe through which the solution enters.

K is the pipe through which the solution runs ott.

Fig. 'T shows au installation of several tanks, and the gold solution runs from one central compartment l) to a second in the next succeeding tank through suitable pipes a. In this ligure L is the cistern containingthe gold solution to be treated. M lll is a series of electrolyzcrs through which the solution passes and yields its gold. N is the colecting-ta-nk in case the solution has to pass again through the electrolyzcrs to be thoroughly exhausted. I is a pump which sends back the solution to the feeding-cistern L.

The simplest apparatus for elcctrodeposition of gold, and the one which I prefer, consists of tanks withoutpartitions, and which I will illustrate as follows: In Fig. 3, Ais the tank along the sides of which are suspended .two peroxidizcd-lead anodesC C, which are perforated and do not reach the surface of the in which a plate of copper or other convenient metal is immersed and is connected with the negative pole of the generator of electricity. Iroper means are adopted to prevent any contact between the anodes C C and the numerous amalgamated perforated plates, ganzes, or network, which dip inthe mercury, till up the tank, and work practically each as a mercurial cathode. There is more eiiiciency, conductivity, and economy in using this tank without compartments than the two othcrs'I have hereinbefore ,described and illustrated.

-Instead of arranginglengthwise my anodes and cathodes in a tank, I may have them disposed crosswisc,'as in Fig. 4, and in such a case I have one perforated anode C for every group of twelve orlifteen cathodes G. The anodes are all connected outside to a bar c, and the eathodes dip in the layer of mercury E and are supportedby the comb y. The advantages of this last arrangement are that I can have a very long tank without the trouble of using long peroXidized-lead plates and amalgamated plates, which it is difficult to keep apart and parallel without the risk of shortcircuitinf..

Fig. 6 shows a perforated anode made of lead peroxdized by one of the known means. The anodes are fixed in a slate or paraiiined wood frame c'. The anodes slide in grooves c2, cut in the walls of the tank, so as to be straight between the cathodes, which are kept apart from each other bymeans of convenient separators, so as to have their two faces in contact with the gold solution. The frame c prevents contact with the eathodes, and its lower part is high enough to render impossible the contact of the anode with the layer of mercury.

I am aware that gold has been deposited ou layers of mercury or amalgamated plates by aid of electricity, but to the best of my knowledge no appara-tus has ever been constructed such as the one Ihave described, in which in presence of peroxidizeddead anodes, which. are perforated, the 'combination of a mercnrial cathode with numerous amalgamatcd perforated plates, or wire networkl ttc., secures an intimate and perfect contact of the gold -solution with every particle of an enormous amalgamated surface, which fills up-the compartment and acts as a cathode, thus helping in the recovery of the gold which the layer of mercury has not complete] y citected.

The great advantages of this process are 9 that the rate of circulation of the gold solution can b c much more rapid; that the installation of tanks is less costly, since in a few tanks more surface of active cathode is available for the deposition of gold than in the loo usual apparatuses for eleetrodepositio'n'; that it requires less mercury; that the conductivity is at its maximum; that the perforated plates, &c., being incontaet with the mercury, do not require terminals, connections,

and that the slightest trouble, and without interfering with the operation, each of them can be withdrawn from the tanks and replaced by other plates for the cleaning up.-

Having now described my invention, what no In an apparatusfor the electrodeposition of gold and silver from a solution, a tank provided with-'one or more anodes and a series of amalgamated cathodes, each cathode consisting ot' perforated, skeleton, or network plates and a layer ofv mercury in the bottom of the tank into which each of the cathodes dips, said layer of mercury being connected with the negative pole of electricity thereby 12o constituting a common vehicle for the current from all the cathodes while at the same time maintaining the said cathodes 'const-antly amalgamated.

In testimony whereof I subscribe my signa- 12 5 ture in presence of two witnesses.

' EMILE ANDREOLI.

Witnesses:

FREDERICK J. IIANBURY, THOMAS WILLIAM TULIJETT. 

